Submerged-screen sizer and separator.



No. 803,550. PATENTED NOV. 7, 1905. J. M. GALLOW.

SUBMERGED SCREEN SIZER AND SBPARATOR. APPLICATION FILED FEB-10, 1905.

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. PATENTED NOV. 7, 1905. J. M. GALLOW. SUBMERGED SCREEN SIZER ANDSBPARATOR.

APPLICATION FILED I'EB. 10, 1905.

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JBHN M.CALLOW PATENTED riov. 7, 1905.

J. M. GALLOW. SUBMERGBD scam: sxzm AND SBPARATOR.

APPLICATION FILED FEB-10. 1906.

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1 9 wow N0- 803,550. PATENTED NOV. 7, 1905.

J. M. GALLOW.

SUBMERGED SGfiEEN SIZER AND SEPARATOR. APPLICATION FILED PEB.10. 1905 4SHEETS-SHBET 4.

UNITED STATES PATENT OFFICE.

SUBIVIERGED-SCREEN SIZER AND SEPARATOR.

Specification of Letters Patent.

' Patented Nov. 7, 1905.

Application filed February 10 1905- selifll 1 To all whom it mayconcern.-

Be it known that 1, JOHN M. CALLow, asubject of the King of GreatBritain, and a resident of Salt Lake City, Utah, have invented certainnew and useful Improvements in Submerged Screen Sizers and Separators,of which the following is a specification accompanied by drawings.

This invention relates to improvements in screening-machines, and moreparticularly to that class of screening-machines having a flatperforated sheet or screen-cloth lying in a horizontal or inclinedposition on which the ore or other material to be screened is placed. Insuch machines, by means of suitable shaking mechanism, pieces smallenough to pass through the holes are shaken through and the oversizeportions are retained and by the action of the machine are continuouslydischarged, thus eifecting a separation of the fines from the coarse.

The invention has special reference to the screening of wet material,although the machine may be utilized with any ,kind of material to whichit is applicable.

Many difficulties have heretofore been met with in screening wetmaterial of any kind on horizontal or inclined screens, the principalofthese difliculties consisting of the fact that as soon as the pulpstrikes the screen the water passes through, leaving the ore in such aplastic condition that perfect work is impossible even when assisted byan excessive vibration of the screen or the addition of large volumes ofwater to keep the pulp in a dilute state.

This invention has for its objects to avoid the disadvantages attendantupon the use of screening apparatus of the character referred to,obviate the difficulties heretofore met with, improve such apparatus,and render it much more efficient in operation.

To these ends the invention consists of apparatus for carrying out theabove objects embodying the features of construction, combinations ofelements, and arrangement of parts having the general mode of operationsubstantially as hereinafter fully described and claimed in thisspecification and shown in the accompanying drawings, in which- Figure lis a longitudinal vertical sectional View of the machine on the line A Bof Fig. 3. Fig. 2 is a plan view of the machine. Fig. 3 is a transversesectional view of the same on the line C F of Fig. 1. Fig. 4 is anenlarged detail transverse sectional view of the device for tighteningthe screen-cloth. Fig. 5 is alongitudinal sectional fragmentary view ofa modified form of the apparatus. Fig. 6 is'a fragmentary plan view ofthe same. Fig. 7 is a transverse sectional view of the same, takenpartly through the body of the screen-sizer and partly through theoversize discharge.

Referring to the drawings, A represents a tank or box containing thebody of water in which the screening is done. In this instance it ispreferable to move the screen J relatively to the boX A, although otherconstructions and arrangement of apparatus may be found suitable forcarrying out the objects in view without departing from the spirit ofthe invention. Contained in the tank A is a floating frame Cr, suitablyconnected, as by means may be substituted for that shown in thediagram,the apparatus shown being preferably a Wilfiey motion. The screen-frameH, as shown, is carried by the floating frame Cr, and thescreening-cloth J is stretched upon the screen-frame. The screen, asshown, terminates in the inclined oversize dischargelip K.

The screen-frame is suitably secured to the floating frame G, as shownin this instance, said screening-frame resting upon the ledges G, whichform a part of the floating frame G, and the bolts and keys P and angleQ firmly secure the screen-frame in place. By drawing out the keys thescreen-frame may be quickly loosened and readily removed for repairs ora duplicate frame inserted in its place.

The boX A is provided with a sloping bottom B, at the junction of whichwith the sides of the tank are arranged a series of orifices N, whichmay be provided with adjustable gates or reducing-plugs N in accordancewith the quantity of water used.

Along the sides of the machine are provided overflow-weirs C. Gutters 1)lead from the weirs C to the downtake-pipes E and thence to the laundersF.

The screen-frame H is preferably provided with a blind-feed sole-plate Gat its receiving I end, on which the ore and pulp fall from the feed-boxM and over which it spreads before reaching the delicate screen-cloth.The frame H is also provided with projecting sides or edges M, each ofwhich is cut down or recessed for a distance equalto the length of thescreen-cloth. The edges are then preferably rounded off to formweir-overflows over which the water may flow down through thelongitudinally -extending openings or slots 0 in the floating frame G,and from thence into the tank A. The overflow-weirs C are substantiallyon the same level as the screen-cloth J, so that the surface of thescreen-cloth is approximately coincident with the surface of the waterin the tank.

According to this invention the screen-surface in the tank is alwayskept submerged in a quiescent water-bath, so that the separation of thefines from the course shall take place, as it were, in a water-bath. Toprevent the ore from rushing over the end before it has had time toscreen properly, the inclined and pivoted lip K is provided, which mayhave suitable means in connection therewith for altering its angle ofinclination. The top edge of the lip K is preferably somewhat above thewater-level, but instead the whole length of the screen may be slightlyinclined, in which case the discharge end of the screen will be abovethe level of the water in the tank. The screen may, as shown, besupported in the tank for horizontal movement and may be arrangedhorizontally or else inclined, as described; but in this instance and toillustrate the invention it is arranged substantially horizontally.

In screening ores it is very desirable that the oversize ore shall passfrom the screen substantially free from muddy water and slime, and thisis another reason for making the discharge end of the screen higher thanthe water-level in the tank, it being understood that the inclined lip Kwhen employed is to be considered a part of the screen for this purpose.The oversize ore after leaving the screen does not again come intocontact with the muddy water of the tank containing the screen fromwhich it is discharged, and consequently it is practically free fromslime and in much better condition for subsequent treatment, such ascrushing, &c.

In the operation of the machine such as described in accordance withthis invention it is important that provision should be made for thefree discharge of any air which may accumulate under the surface of thescreen, and this end is accomplished by building the screen-framewithout transverse obstructions or projections along the under side ofthe screen, so that air-bubbles that may form and might accumulate onthe under side of the screen can travel forward until they come to theinclined lip K and there be freely discharged into the open space Kunder the lip and between the lip and the surface of the water. Thearrangement of the screen in a slightly upwardly inclined position stillfurther assists in the free discharge of any entrained or accumulatedair under the screen cloth. It will be seen that a weir K is provided atthe end of the tank underneath the lip K of such height that the screenis properly submerged, and the lip is adjusted so that there is an openspace between the top of the weir K and the bottom of the lip K.

The floating frame Gr, carrying the screen, is so hung from thesuperstructure V that the screen may be adjusted vertically. As shown,the rods V at the receiving end of the frame are connected to an idleshaft W. At the front end they are connected to the levers X, which arekeyed onto the rocker-shaft Y, to which in turn is connected the leverZ, having a counterbalance M suspended therefrom.

In the operation of the machine, under certain conditions of feed andwater it is sometimes found desirable to support the front end of thescreen-cloth above the surface of the water, leaving the back or feedend submerged. It will be seen that the inclination of the screen may bechanged and regulated while the machine is in motion by varying theWeight of the counterbalance M or by varying the leverage. As shown, theleverage may be varied by moving the weight along the lever Z, Thefloating frame G is preferably made of wood or other buoyant material,so that it is partly, if not wholly, supported and floated by thesurrounding water, and one use of the counterbalance M is to assist insupporting and buoying up the frame and to counterbalance the weight ofthe ore particles upon the surface of the screen.

In the operation of the machine power is applied to the differentialmotion H by a suitable belting and the screen shaken. The feed or pulpis fed from the feed-box M and is distributed over the full wid th ofthe screen through the holes m and falls onto the blindfeed sole-platebelow, .from whence it passes to the screen-cloth, the water and thefines passing through the screen and in a short space of time fillingthe tank A, while the oversize-portions are propelled forward up andover the inclined lip K and into the oversize spout L. Part of the wateris discharged through the orifices N into the catch-launders F and partover the overfloW-weirs C at the sides of the tank, the orifices N beingso regulated that there shall always be an overflow at C. By this meansthe water-level in the tank is maintained at a substantially uniformlevel.

The relationship between the surface of the front end of the screen andthe surface of the water in the tank should remain substantiallyconstant, and the method of suspending the frame as described and thebuoyancy of the frame enable this to be done. In the event ITS of asudden increase in the-quantity of water coming into the machine theorifices N can discharge only a definite quantity and the surplus passesover the weirs C, consequently increasing the depth of the water overthese weirs, and were it not for the buoyancy of the frame and the modeofsuspens'ion the front end of the screen would be submerged totoo greatan extent. As soon, however, as the depth of water in the tank increasesthe frame G is raised correspondingly, and the degree of submergence isthereby maintained substantially constant. Onemode of suspending thescreen in the tank has been described and has been found to operateefiicientl y and well; but other arrangements may be constructed forcarrying out the same objects, and the invention is not to be understoodas limited to the construction shown in the drawings. The arrangement oflevers and counterbalance shown for suspending the screen has theadvantage that provision is afforded for cleaning the screen by plungingit up and down in the water-bath, causing the water to be impelledthrough the meshes of the screen, and thereby forcing out slimes andother foreign material that may have become entangled therein.

According to the construction of this apparatus if the water isprevented from passing through the screen with all the fines because ofthe choking of the screen by a surcharge of material it will be seenthat the water will rise above the top of the rounded edges of thescreen sides M and fall into the opening 0 and thence into the tank A.This overflow supplies the loss under the screen-cloth, raises thesurface of the water there, and again brings about the free settlingcondition which is requisite for the proper operation of the machine,and in due time the machine resumes it proper functions.

Improved means are provided for tightening the screen-cloth.(Illustrated in detail in Fig. 4.) At substantially the center line ofthe screen-frame is arranged a center bar R, which is grooved along itswhole length to receive the tightening device, consisting in thisinstance of the rod or piping T, arranged over the groove and adapted tobe forced thereinto by suitable means, as the thumb-nuts S on the boltsS. As the piping T is forced into the groove it 'carries with it thecloth, thus tightening the screen. To take the strains of thistightening and prevent the distortion of the screen-frame, struts orbraces U are provided, of thin iron,*preferably, set edgewise with theline of motion, so as to cut through the water and make as littledisturbance as possible therein.

In Figs. 5, 6, and 7 a modified form of apparatus is shown havingdifferent means from those already described for leading off the surplusof water in the feed following a rush of comparatively dry material ontothe screen.

In the construction shown in Figs. 5, 6, and 7 both the tank A andscreen are movable, by way of illustration, although this need notnecessarily be the case, and one may be movable relatively to the other.In order to carry off the surplus water, as described, pairs ofangle-irons or guides 1, of suitable material, are arrangedlongitudinally substantially in the middle of the screen. The tops ofthese angle-irons or guides 1 are slightly above the normal surface ofthe water on the screen, and they serve to confine the material to thescreen and leave a bare space between them, through which surplus wateris discharged in sufiicient quantity to rise and flow over the edges ofthe angle irons. Preferably these angle-irons are continued beyond thescreen-cloth up to the edge of the dischargelip K, so that any materialaccidentally getting into the channel between said angle-irons isproperly discharged, and material on either side of the irons isprevented from finding its way around the ends into said channel.According to this construction if the water which normally passesthrough the screen-cloth with the fines is prevented from doing so bythe choking of the screen it will rise above the top of the guides 1 andflow through the screen between them, which is kept clear from material.This overflow supplies the loss under the screen-cloth, raises thesurface of the water-level, and brings about the free settling conditionrequisite for proper operation. I have discovered that by submerging thescreen area any large particles placed thereon are thereby put into whatmay be termed a free settling condition, for by reason of being immersedthey are in a condition to arrange themselves without friction due toeach other, and therefore find a means of exit through thescreen-openings in the easiest possible manner. An action which causesthe particles to assume a free settling condition more readily admits oftheir falling through the screen-openings. According to this inventionanother action takes place, which may be explained as follows: It hasbeen found that if a submerged screen is simply moved up and down in thewater or any such receptacle containing ore particles is so moved-inother words, if a jigging or pumping motion be given to itthe coarseparticles will go to the bottom and the fine will come to the top, or ifa hollow cylinder, as a round screen, containing ore particles isrevolved it will be found that the coarsest pieces are next the meshesof the screen and the finest farthest from it, a condition in both caseswhich is diametrically opposed to efficiency; but I have discovered thatif a screen is shaken horizontally the reverse is the case. The finestpieces will be found Therefore screening apparatus constructed andoperated in accordance with this invention is immeasurably increased inefiiciency and capacity per square foot of screen area. It will beobserved that in my apparatus I remove the rejections by propelling themforward or forward and upward when the screen is inclined to an inclinedlip, and this is accomplished by means of the particular progressivefeeding motion imparted to the screen.

Obviously some features of this invention may be used without others,and the invention may be embodied in widely-varying forms.

Therefore without limiting the invention to the constructions shown anddescribed nor enumerating equivalents, I claim, and desire to secure byLetters Patent, the following:

1. In a submerged-screen sizing apparatus, the combination with the tankand screen supported therein, of means for imparting a differentialreciprocating shaking motion to the screen in a horizontal direction, arelief area provided at the middle portion of the screen, means forincreasing the escape of surplus water above the screen-cloth, means fordischarging material tending to block said relief area, and means forkeeping material to be screened off of said relief area except underabnormal conditions of feed.

2. In a submerged-screen sizing apparatus, the combination with a tankadapted to contain water, of a carrying-frame hung wholly within thetank and buoyantly supported on the surface of the water therein, ascreenframe and screen connected to the carryingframe within the tankand submerged slightly below the surface of the water, means forimparting a differential reciprocating shaking motion to thecarrying-frame in the tank in a horizontal direction, means formaintaining a constant degree of submergence of the screen, means forsupplying any lack of water below the screen from the surface waterabove the screen, and means for permitting the free discharge of airbeneath the screen.

3. In a submerged-screen sizing apparatus,

the combination with a tank adapted to contain Water, of acarrying-frame'hung wholly within the tank and buoyantly supported onthe surface of the water therein, a screenframe and screen connected tothe carryingframe within the tank and submerged slightly below thesurface of the water, means for imparting a differential reciprocatingshaking motion to the carrying-frame in the tank in a horizontaldirection, means for delivering material to be screened to one end ofthe screen, means for maintaining the water at a substantially uniformlevel in the tank and below the delivering end of the screen, and meansfor permitting the free discharge of air from beneath the screen.

4. In a submerged-screen sizing apparatus, the combination with a tankadapted to contain water, of a carrying-frame hung wholly within thetank and buoyantly supported on the surface of the water therein, ascreenframe and screen connected to the carryingframe within the tankand submerged slightly below the surface of the water, means forimparting a differential reciprocating shaking motion to thecarrying-frame in the tank in a horizontal direction, an inclined lip atthe discharge end of the screen above the level of the water in the tankand over which the oversize ore passes from the screen, a weir arrangedbeneath said lip with a space between the top of the weir and the lip,permitting free discharge of air and surface water under thescreen-cloth, means for maintaining a constant degree of submergence ofthe screen, and means for supplying any lack of Water below the screenfrom the surface water above JOHN M. (JALLOW.

Witnesses:

D. J. NEVILL, F. E. J OHNSON.

